Coupling device for twin outboard motors



A. c. FLETCHER 2,968,192

COUPLING DEVICE FOR TWIN OUTBOARD MOTORS 2 Sheets-Sheet 1 Jan. 17, 1961 Filed Sept. 2, 1959 INVENTOR. v A. C. Fiet /fer' Jan. 17, 1961 Filed Sept. 2, 1959' A. C. FLETCHER COUPLING DEVICE FOR TWIN OUTBOARD MOTORS 2 Sheets-Sheet 2 INVENTOR.

United States Patent COUPLING DEVICE FOR TWIN OUTBOARD MOTORS Albert C. Fletcher, th and Missouri Sts., Oklahoma City, Okla.

Filed Sept. 2, 1959, Ser. No. 837,626

7 Claims. (Cl. 74-471) This invention relates to an improved device for coupling together side-by-side mounted outboard motors so that the same may be steered jointly.

In recent years there has been an enormous increase in the use of boats fitted with outboard motors. While most of such boats are equipped with one motor, the popularity in the use of two motors is increasing. Two motors, of course, provide greater dependability. Another advantage in the use of two motors is that they can be so designed that the propellers rotate in opposite directions. This is important because counter-rotation cancels out all torque caused by propeller rotation. The elimination of the torque makes the boat easier to control in both smooth and rough water. Furthermore, this feature provides greater stability when traveling across the wakes of other boats. However, there are certain disadvantages inherent in the use of two motors if certain precautions are not taken. As is 'well known to those skilled in this art, the rudder is an integral part of the motor and it is turned by turning or rotating the entire motor. Obviously, when two motors are used it will be necessary to rotate each motor exactly the same amount; otherwise, to a certain degree, the two motors will tend to pull against each other.

In addition to providing means by which an outboard motor may be rotated in a horizontal plane for steering, the motor is so designed to permit free movement of the motor in a vertical plane-popularly called tilting. This latter movement is important because ,it greatly reduces the possibility of damage to the motor if a submerged rock, log, or other object is struck. When the motor is in a tilted position, the operator will have little or no control over the boat.

The present invention contemplates a coupling device for twin outboard motors wherein precise control of the motors in a horizontal plane is attained for accurate steering, yet either one of the motors may betilted without affecting the position or operation of the other motor. Broadly stated, the present invention may be defined as a device for coupling together a pair of side-by-side universally mounted outboard motors fitted with carrying handles to provide for joint steering movement and allow independent tilting movement of said motors, comprising an elongated rod, a socket member slidingly carried at each of the opposite ends of the rod for movement lengthwise with respect to the rod, elastic means carried at each end of the rod yieldably retarding movement of the respective socket member lengthwise with respect to the rod, a ball member journaled in each socket member, a shaft secured to each ball member, means connecting each shaft to the carrying handle of one of the motors for pivoting the respective ball member in the respective socket member and moving the respective socket member against the action of said elastic means upon tilting movement of the motor, and means for moving the rod lengthwise to simultaneously pivot the motors laterally.

An important object of this invention is to provide a Patented Jan. 17, 1961 "ice device for coupling a pair of twin outboard motors, wherein the motors will be turned the same amount for a steering operation and precise control of the steering of the boat on which the motors are mounted is obtained.

Another object of this invention is to provide a coupling device for twin outboard motors wherein either of the motors may be tilted while the othermotor remains in operating position and without aifecting the function of the other motor.

A further object of this invention is to provide a coupling device for twin outboard motors which may 'be easily adjusted for use on substantially any twin outboard motor installation.

Another object of this invention is to provide accurate steering of twin outboard motors, with a minimum of friction in the coupling between the motors.

A still further object of this invention is to provide a coupling device for twin outboard motors which is simple in construction, may be economically manufactured, and will have a long service life.

Other objects and advantages of the invention will be evident from the following detailed description, when read in conjunction with the accompanying drawings which illustrate my invention.

In the drawings:

Figure 1 is a plan view of the stern of a boat having a pair of outboard motors mounted thereon and illustrating the use of the present invention.

Figure 2 is a side view of the structure shown in Fig. 1, with the stern of the boat shown in section.

Figure 3 is an enlarged perspective view of a coupling device embodying this invention.

Figure 4 is an enlarged sectional view as taken substantially along lines 44 of Fig. 3.

Referring to the drawings in detail, and particularly Figs. 1 and 2, reference character 10 designates a boat having twin outboard motors 12 mounted on the stern wall 14 thereof. The motors 12 are each secured on the stern wall 14 by a suitable hinged mounting 16 which allows each motor to be turned about a substantially vertical axis for steering the boat 10 and which allows each motor 12 to be tilted forwardly with respect to the boat 10 in such a manner as to raise the propeller 18 of the respective motor, as is common in the art. The specific motors 12 and mountings 16 form no part of the present invention and are, therefore, not described in great detail herein. It is only necessary that each of the motors 12 be mounted in such a manner as to be capable of tilting and pivoting laterally. Also, a carrying handle 20 extends forwardly from each of the motors 12in a substantially horizontal plane When the motors 12 are in their operating positions, with each handle 20 normally being provided on the respective motor 12 for lifting and carrying the motor.

The present invention comprises a novel coupling device generally designated by'reference character 22 which is attached to the carrying handles 20of the motors 12 for simultaneously steering the motors 12 in response to forces transmitted through a suitable steeringlinkage 24. In a preferred installation, the steeringflinkage 24 comprises a flexible shaft extending from the cockpit (not shown) of the boat 12 and suitably guided by brackets 26 along one side of the boat, such that the steering linkage may be easily bent and provide an eflic'ient steering of the motors 12. The rearmost end '28 ofythe steering linkage 24 is suitably secured to either .end of the present coupling device '22for providing lengthwise movement of the device 22 and steeringo'f the-motors;12, as will be more fully hereinafter set forth.,

In a preferred form (see Fig.3.), the couplingdevice 22 comprises an elongated rod 30 formed in two sections and interconnected by a suitable turnbuckle 32 for easily and efiiciently adjusting the overall length of the rod 30 and adapting the device 22 to various outboard motor installations. As is common in the art, the turnbuckle 32 is threaded onto the adjacent ends of the sections of the rod 30 to adjust the overall length of the rod 36 upon turning of turnbuckle 32. A tubular housing 34 is mounted on each of the opposite ends of the rod 30 to slidingly receive a socket member 36, as shown in Fig. 4, which translates movement of the rod 30 to the outboard motors. The inner end wall 38 of each housing 34 is provided with a bore or aperture 40 of a size to slidingly receive the respective end portion of the rod 30. A circumferential flange or shoulder 42 is provided on the extreme end portion of each rod 30 in any suitable manner within the respective housing 34 to contact the inner end 38 of the respective housing and prevent removal of the housing from the rod 30 during operation of the device. It will be apparent upon examination of Fig. 4 that each flange 42 is larger in diameter than the respective aperture 40, but is smaller in diameter than the inner diameter of the respective housing 34, such that each housing 34 may be telescoped over the respective outer end portion of the rod 30, but will be prevented from moving off of the rod, as previously indicated.

Each socket member 36 preferably comprises a pair of pistons 44 having their adjacent faces 46 concaved to provide a socket for a ball member 48. Each socket member 36 is yieldably retained in a predetermined position in the respective housing 34, and therefore in'a predetermined lengthwise position with respect to rod 30 by a pair of helical compression springs 50. One of the springs 50 is anchored against one side of the socket member 36 and against a plug 52 suitably secured in the outer end of the housing 34. The other spring 50 is anchored between the other side of the socket member 36 and the respective stop flange 42 on the rod 30. It will therefore be observed that the springs 50 constantly tend to move the respective housing 34 into a position with the stop flange 42 in contact with the end wall 38 of the housing, and constantly tend to move the socket member 36 into a predetermined position within the housing 34, depending upon the relative strengths of the springs 50. In a preferred embodiment, each pair of springs 50 are of the same strength to normally position the respective socket member 36 centrally in the respective housing 34.

A shaft 54 is secured to the ball member 48 and extends loosely through an enlarged slot 56 formed in one side wall of housing 34. In the preferred embodiment, the slot 56 will be along the lower crown of the housing 34, and the shaft 54 will normally extend vertically downward from the respective ball 48 and socket 36. The lower end portion of each shaft 54 extends loosely through an aperture 58 formed in a plate member 60 and is journaled to the respective plate 60 by means of a ball bearing unit 62. The inner race of the bearing 62 is preferably secured on the shaft 54 and the outer race of the bearing 62 is pressed into a complementary recess 64 in the lower face of the plate 60. The bearing unit 64 is retained in the desired position and provided with the desired load by means of a flange 66 around the shaft 54 and a suitable nut 68 threaded on the lower end of the shaft. A bracket member 70 is secured on the lower face of each plate 60 by means of suitable connectors 72 and is shaped in any suitable manner for rigid attachment with carrying handle 20 of one of the motors 12. In a preferred embodiment, the clamp 70 of each plate 60 is secured on the respective carrying handle 20 in such a manner that the respective plate 60 is retained parallel with the plane of the respective carrying handle 20, as illustrated in Fig. 2, such that the respective shaft 54 extends at a right angle to the plane of the carrying handle.

In operation of the device 22, when both of the motors 12 are extended vertically as illustrated in Fig. 2, the steering linkage 24 is actuated to provide endwise or lengthwise movement of one of the housings 34. It will be understood that the rear end 28 of the steering linkage 24 is suitably secured to the outer end of one of the housings 34, as illustrated in Fig. 1. Movement of one of the housings 34 is translated through the respective springs to the rod 30 and through the respective springs at the opposite end of the device to the other housing 34. When the rod 30 is moved lengthwise, the springs 50 urge the socket members 36 in the same direction to simultaneously turn the motors 12 and steer the boat 10. It should also be noted that the springs 50 at each end of the device 22 properly position the socket members 36 at the end of the lengthwise movement of the device, such that both of the motors 12 will be turned the same amount and will be yieldingly retained in the turned positions until the device 22 is again moved lengthwise.

When it is necessary or desirable to tilt one of the motors 12, as when the propeller 18 on the lower end of the motor strikes a log or other obstruction, the respective shaft 54 is pivoted in the respective socket member 36 as the respective end portion of the device 22 is moved downwardly. The springs 50 accommodate the adjusted position of the respective socket member 36 which is due to a variation in the distance between the carrying handles 20 when one of the motors is tilted forwardly, such that a minimum force is applied on the carrying handle 20 of the other motor 12, and the motor 12 which is not intentionally tilted will remain in its fixed vertical position for propelling the boat 10. It may also be noted that even when one of the motors 12 is tilted, the motors 12 will be simultaneously turned laterally upon movement of the steering linkage 24 to provide an accurate steering of the motor 12 which remains in operating position in substantially the same manner as when both of the motors 12 are in operating position. It should also be noted that since the shaft54 associated with a tilted motor is retained at a right angle to the plane of the respective motor carrying handle 20, the respective shaft 54 will remain efiiciently journaled by the bearing unit 62 to provide turning movement of the motor with a minimum of friction.

From the foregoing, it will be apparent that the present invention provides a novel coupling device for twin outboard motors wherein the motors will be simultaneously and accurately steered upon actuation of the steering mechanism of the boat on which the motors are mounted. Each of the motors is connected to the coupling device by a ball and socket member and by elastic means which yieldably retain the socket members in predetermined positions with respect to the remaining portion of the coupling device to assure that the motors will be turned the same amount when the coupling device is moved lengthwise. It will be further apparent that either of the motors may be tilted forwardly Without affecting the operating position or efiiciency of the remaining motor, and the remaining motor may still be accurately steered to control the boat on which the motors are mounted. It will further be apparent that the present coupling device is simple in construction, may be economically manufactured and will have a long service life.

Changes may be made in the combination and arrangement of parts or elements as heretofore set forth in the specification and shown in the drawings, it being understood that the changes may be made in the precise embodiment disclosed without departing from the spirit and scope of the invention as defined in the following claims.

I claim:

1. A device for coupling twin outboard motors fitted with carrying handles to provide joint steering movement and allow independent tilting movement of the motors, comprising elongated rod means, a socket member slidingly carried at each of the opposite ends of the rod for movement lengthwise with respect to the rod means, elastic means carried at each end of the rod means yieldably retarding movement of the respective socket member lengthwise with respect to the rod means, a ball member journaled in each socket member, a shaft secured to each ball member, means connecting each shaft to the carrying handle of one of the motors for pivoting the respective ball member in the respective socket member and moving the respective socket member against the action of said elastic means upon tilting movement of the motor, and steering means for moving the rod means lengthwise to simultaneously pivot the motors laterally.

2. A device as defined in claim 1 wherein said rod means comprises a pair of rods arranged in tandem and a turnbuckle connected to the adjacent ends of the rods to adjust the length of the rod means.

3. A device as defined in claim 1 characterized further to include a tubular housing carried on each of the opposite ends of the rod means and having a slot in one wall thereof, said socket member being slidingly disposed in the respective housing with the respective shaft extending loosely through the slot in the respective housing, and said elastic means at each of the opposite ends of the rod means being in two parts and positioned in the respective housing on opposite sides of the respective socket member.

4. A device defined in claim 3 wherein each of said housings has an aperture in one end thereof slidingly receiving the respective end of the rod means to retain the housings aligned with the rod means, and wherein each end of the rod means has a stop thereon of a size to prevent the housing from being removed off of the respective end of the rod means, and wherein said elastic means at each end of the rod means is in the form of a pair of helical springs anchored at each side of the respective socket member, with one spring being between the socket member and the respective stop on the rod means, and the other spring being between the socket member and the other end of the respective housing.

5. A device as defined in claim 3 wherein each socket member is in the form of two piston members slidingly disposed in the respective housing and having their adjacent faces concaved to form a socket for the respective ball member.

6. A device as defined in claim 1 wherein said connecting means comprises a bracket for a rigid attachment to the respective motor carrying handle and having an aperture therethrough extending at right angles to the plane of the respective carrying handle and being of a size to receive the respective shaft, and a bearing unit rotatably securing each shaft in the respective bracket aperture.

7. A device for coupling twin outboard motors fitted with carrying handles to provide for joint steering movement and allowing independent tilting movement of the motors, comprising an elongated rod means adjustable in length, a tubular housing on each of the opposite ends of the rod means having a slot in one side wall thereof, a pair of pistons slidably mounted within each of said housings with the facing surfaces of said pistons being concave, spring means in each housing urging the respective pair of said pistons together into a pre-determined position in the respective housing, a pair of shafts, one end of each shaft extended loosely through the slot in one of the housings and having a ball-shaped enlargement thereon slidingly fitting between the concave faces of the respective pair of pistons for universal pivotal movement of the shaft with respect to the respective housing, means for journaling the opposite end of each shaft to the carrying handle on one of the motors and retaining the respective shaft extended at a right angle to the plane of the respective carrying handle, and means for moving said rod means lengthwise to provide joint steering movement of the motors regardless of whether one motor is pivoted vertically with respect to the other motor.

Weber May 8, 1956 Prier Aug. 18, 1959 

